TSearch2 / UTF-8 and stat() function

Another UTF-8 thing I forgot:

fts=# SELECT * FROM stat('SELECT to_tsvector(''simple'', line) FROM fts;');
ERROR: invalid byte sequence for encoding "UNICODE": 0xe2a7

The query inside the stat() function alone works fine. I have not set
any client encoding. What breaks it? It works as long the inside query
does not return UTF-8 in vectors.

Thanks.

--
Regards,
Hannes Dorbath